Healthcare reform has resulted in sicker patients being cared for in the home and extended care facilities. Patients who require long term mechanical ventilation represent a special needs group within this population. The single greatest impediment to quality of life in the ventilator assisted individual is portability. Current generation ventilators are large, heavy (30 lbs), and require significant battery power. This application proposes to build a small, lightweight flow generator that produces air via an energy efficient turbine. The investigative plan will refine the turbine to minimize size (<2 lbs), provide a flow of 160 lpm, provide a pressure of 120 cm H2O, and increase efficiency from the current turbine technology by over 100%. Following refinement of the flow generator, a precise control system for delivery of volume and pressure breaths will be designed to meet the needs of the home care population from pediatrics to adults. The proposed ventilator will have immediate commercial potential users of this new technology. In Phase II the investigators will develop a complete portable ventilator based on the Phase I roots blower flow system. PROPOSED COMMERCIAL APPLICATIONS: The turbine technology here proposed would be used as the "engine" for future portable ventilators. It is estimated that worldwide from 2 to 3 million patients per year require some form of mechanical ventilation. As of the year 2000, it is estimated that approximately 23,400 ventilators will be sold, yielding about $392 million dollars in annual revenue. Within this broad market, the portable ventilator technology here proposed would be essential for homecare, transport, military field applications and alternate care environments.